Applications of accumulated knowledge in cognitive psychology have led to the creation of different interventions to improve cognitive performance in real life settings. In particular, applied research has demonstrated that cognitive performance in various domains can be enhanced by non-invasive computerized cognitive training programs (Green & Bavelier, 2008; Willis et al., 2006). While most computerized cognitive training studies have focused on cognitive skills related to memory, attention and executive functions, few reports have documented attempts that are aimed to improve linguistic abilities in general, and language comprehension in particular, among literate adults.
Nevertheless, in recent years much progress has been achieved in the understanding of underlying neuro-cognitive processes of language comprehension. As opposed to the outdated notion that all language functions are exclusively lateralized to the left hemisphere (LH), it is now clear that semantic processing in the right hemisphere (RH) has a unique contribution to language comprehension and creative aspects of language (for reviews, see Beeman & Chiarello, 1998; Kahlaoui, Scherer, & Joanette, 2008; Lindell, 2006; Mitchell & Crow, 2005).
Numerous conceptualization efforts have been made in order to account for the asymmetric lateralization of language processing in the brain (for review, see Dien, 2008). Jung-Beeman (2005) has suggested the BAIS model (Bilateral Activation, Integration and Selection) as a comprehensive theoretical framework for the recent findings on the hemispheric asymmetry in semantic processing. According to the model, bilateral semantic processes of activation, integration and selection interact in order to process language.
According to the BAIS model (Jung-Beeman, 2005), the RH coarse semantic processing patterns (diffused semantic activation, leading to weak activation of multiple concepts remotely associated to the input, followed by their integration and selection) are efficient for natural language comprehension, verbal creativity and similar high-order skills that require the person to integrate distant and initially irrelevant information. Fine LH semantic processing patterns (rapid activation, focused on dominant features which are tightly linked to the input, followed by efficient integration and selection) are crucial for most language comprehension tasks, as well as for language production, as they benefit from the quick activation and selection of contextual relevant salient meanings—but are less effective when multiple or less salient meanings are required. For example, when participants generate a typical use for a noun (e.g., airplane—fly) the LH is more involved, but when requested to generate an unusual use (e.g., airplane—build) higher involvement is detected in the RH (Seger, Desmond, Glover, & Gabrieli, 2000). Accordingly, as argued by Jung-Beeman, coarse semantic coding patterns underlie higher level linguistic tasks, such as inference drawing, metaphor and humor comprehension, as well as message level comprehension tasks (deriving themes, generating optimal sentence endings, determining narrative sequence and inconsistencies) (Jung-Beeman, 2005; on the notion of coarse and fine semantic coding see also Beeman et al., 1994, Beeman, 1998).
Accumulated publications of controlled cognitive training studies have demonstrated that the learning of new cognitive skills and the improvement of existing skills is possible across different populations and ages. For instance, numerous studies have been successful in enhancing cognitive skills in older adults, with or without mild cognitive impairments (for reviews, see Jean, Bergeron, Thivierge, & Simard, 2010; Valenzuela & Sachdev, 2009). The success of training has also been documented in clinical populations, including patients with schizophrenia (for reviews, see McGurk, Twamley, Sitzer, McHugo, & Mueser, 2007; Twamley, Jeste, & Bellack, 2003) and children with ADHD (for review, see Toplak et al., 2008).
More than a few studies have shown long lasting effects of cognitive training, as well as the generalization of the trained skill in daily untrained tasks (also termed ‘transfer’, see Blume, Ford, Baldwin, & Huang, 2010). Unlike other instructional interventions, cognitive training programs engage participants in tasks that stimulate target cognitive processes, allowing participants to explore and acquire new strategies while handling the training tasks, and later use the acquired skills flexibly in untrained tasks. For example, a study with air force pilots, healthy young adults, demonstrated improved real-time flight performance following training on the ‘space fortress’ game (Gopher, Weil, & Bareket, 1994; Hart & Battiste, 1992). A comprehensive clinical trial (n=2832) identified long term effects of cognitive training in healthy older adults, which were expressed in trained skills (memory, reasoning and processing speed) as well as in untrained daily functions, for at least five years after training (Willis et al., 2006). A computer assisted training program for children with ADHD resulted in significant improvements in attention as well as in non-trained academic measures (Shalev, Tsal, & Mevorach, 2007).
Moreover, cognitive training effects are not limited to changes in behavioral performance. Several brain imaging studies have recently revealed training-induced plasticity in the healthy human brain (i.e., Dahlin, Neely, Larsson, Bäckman, & Nyberg, 2008; Erickson et al., 2007; McNab et al., 2009; Olesen, Westerberg, & Klingberg, 2004).
While the aforementioned studies did lead to the transfer of the trained skills into other tasks and situations, other cognitive training studies did not result in transfer effects. Recent reviews of computerized cognitive training programs show that controlled empirical evidence for transfer is limited, due to different causes related to the interventions themselves, the trainability of the target skills, and study design (Green & Bavelier, 2008; Melby-Lervåg & Hulme, 2012; Shipstead, Redick, & Engle, 2010).
While preliminary evidence suggests some promise for linguistic training, the question remains whether cognitive training could induce the improvement of linguistic skills in non-trained linguistic tasks in larger samples.